Akihide Matsumura

EGFR and erbB2 mutation status in Japanese lung cancer patients

Much evidence has accumulated that the epidermal growth factor receptor (EGFR) and its family members are strongly implicated in the development and progression of lung cancers. Somatic mutations of the EGFR gene were found in about 25–40% of Japanese lung cancer patients. More recently, erbB2 mutations are found in about 4% of European‐derived lung cancer patients. We have investigated EGFR and erbB2 mutation status in 95 surgically treated nonsmall cell lung cancer (NSCLC) cases from Nagoya City University Hospital. Seventy‐five adenocarcinoma cases were included. The presence or absence of EGFR and ernB2 mutations of kinase domains were analyzed by reverse transcription polymerase chain reaction (RT‐PCR) amplifications and direct sequences. We have also investigated erbB2 mutation status in 27 surgically treated NSCLC cases followed by treatment with gefitinib from Kinki‐chuo Chest Medical Center. EGFR mutations (CTG→CGG; L858R) were found from 14 of 95 lung cancer patients. We also detected the deletion 1a‐type mutations from 9 patients and deletion 4‐type mutations from 6 patients in exon 19. In exon 20, 4 mutations including 2 novel mutations were found. Total EGFR mutations were present in 35 patients (36.8%). These mutation statuses were significantly correlated with gender (women 73.3% vs. men 20%, p < 0.0001), smoking status (never smoker 69.4% vs. smoker 16.9%, p < 0.0001), pathologic subtypes (adenocarcinoma 45.1% vs. nonadenocarcinoma 12.5%, p = 0.0089) and differentiation status of the lung cancers (well 51% vs. moderately or poorly 18.4%, p = 0.0021). On the other hand, erbB2 mutation was only found from 1 of 95 patients, at exon 20. This patient was female and a never smoker with adenocarcinoma. This 12 nucleotide insertion mutation (2324–2325 ins ATACGTGATGGC) was located in the exon 20 at kinase domain (775–776 ins YVMA). There was no erbB2 mutation in 27 gefitinib‐treated NSCLC patients. In total, we have found only 1 erbB2 mutation from 122 (0.8%) Japanese NSCLC patients. There was a significantly higher erbB2 positive (2+/3+) ratio in EGFR mutant patients (13/25, 52.0%) compared to EGFR wild‐type patients (10/62, 16.1%; p = 0.0247). The NSCLC specimen with erbB2 mutation showed 1+ immunoreactivity. The EGFR mutation status might correlate with the clinicopathologic features related to good response to gefitinib, such as gender, smoking history and pathologic subtypes of lung cancers. However, erbB2 mutation is rare from Japanese lung cancer and is of limited value for molecular target therapy.

Performance Status and Smoking Status Are Independent Favorable Prognostic Factors for Survival in Non-small Cell Lung Cancer: A Comprehensive Analysis of 26,957 Patients with NSCLC

Background: Performance status (PS) is an important factor in determining survival outcome in non-small cell lung cancer (NSCLC) but is generally confounded by stage, age, gender, and smoking status. We investigated the prognostic significance of PS taking into account these important factors. Methods: Retrospective analysis of registry database of the National Hospital Study Group for Lung Cancer (NHSGLC) between1990 and 2005. Univariate analysis was performed using Kaplan-Meier method. Multivariate analysis was performed using Cox proportional hazards model to identify independent prognostic factors. Results: A total of 26,957 patients with NSCLC were analyzed of which 12,613 patients (46.8%) had World Health Organization (WHO) PS = 0, 8,137 patients were never smokers (30.2%), and most of them were females (72.7%). The majority of PS = 0 patients presented with stage I disease (56.9%). Patients with PS = 0 constituted the group with the highest proportion of never smokers (36.7%). There was a significant difference in the median overall survival (OS) between patients with PS = 0 and PS = 1 (51.5 months versus 15.4 months, respectively; p < 0.0001) and among patients with various PS within individual American Joint Committee on Cancer stage (all p values <0.0001). Never smokers had significantly improved median OS than ever smokers (30.0 months versus 19.0 months, respectively; p < 0.0001). Multivariate analysis demonstrated good PS, never smoker (versus ever smoker; hazard ratio = 0.935, 95% confidence interval: 0.884–0.990; p = 0.0205), early stage, female gender, squamous cell carcinoma histology, and treatment were all as independent favorable prognostic factors. Conclusions: PS and smoking status are independent prognostic factors for OS in NSCLC.

EGFR Mutation Status in Japanese Lung Cancer Patients: Genotyping Analysis Using LightCycler

Purpose: Recently, somatic mutations of the epidermal growth factor receptor (EGFR) gene were found in ∼25% of Japanese lung cancer patients. These EGFR mutations are reported to be correlated with clinical response to gefitinib therapy. However, DNA sequencing using the PCR methods described to date is time-consuming and requires significant quantities of DNA; thus, this existing approach is not suitable for a routine pretherapeutic screening program. Experimental Design: We have genotyped EGFR mutation status in Japanese lung cancer patients, including 102 surgically treated lung cancer cases from Nagoya City University Hospital and 16 gefitinib-treated lung cancer cases from Kinki-chuo Chest Medical Center. The presence or absence of three common EGFR mutations were analyzed by real-time quantitative PCR with mutation-specific sensor and anchor probes. Results: In exon 21, EGFR mutations (CTG → CGG; L858R) were found from 8 of 102 patients from Nagoya and 1 of 16 from Kinki. We also detected the deletion mutations in exon 19 from 7 of 102 patients from Nagoya (all were deletion type 1a) and 4 of 16 patients from Kinki (one was type 1a and three were type 1b). In exon 18, one example of G719S mutation was found from both Nagoya and Kinki. The L858R mutation was significantly correlated with gender (women versus men, P < 0.0001), Brinkman index (600 ≤ versus 600>, P = 0.001), pathologic subtypes (adenocarcinoma versus nonadenocarcinoma, P = 0.007), and differentiation status of the lung cancers (well versus moderately or poorly, P = 0.0439), whereas the deletion mutants were not. EGFR gene status, including the type of EGFR somatic mutation, was correlated with sensitivity to gefitinib therapy. For example, some of our gefitinib-responsive patients had L858R or deletion type 1a mutations. On the other hand, one of our gefitinib-resistant patients had a G719S mutation. Conclusions: Using the LightCycler PCR assay, the EGFR L858R mutation status might correlate with gender, pathologic subtypes, and gefitinib sensitivity of lung cancers. However, further genotyping studies are needed to confirm the mechanisms of EGFR mutations for the sensitivity or resistance of gefitinib therapy for the lung cancer.

Phase II Trial of Preoperative Chemoradiotherapy Followed by Surgical Resection in Patients With Superior Sulcus Non–Small-Cell Lung Cancers: Report of Japan Clinical Oncology Group Trial 9806

PURPOSE To evaluate the safety and efficacy of preoperative chemoradiotherapy followed by surgical resection for superior sulcus tumors (SSTs). PATIENTS AND METHODS Patients with pathologically documented non-small-cell lung cancer with invasion of the first rib or more superior chest wall were enrolled as eligible; those with distant metastasis, pleural dissemination, and/or mediastinal node involvement were excluded. Patients received two cycles of chemotherapy every 4 weeks as follows; mitomycin 8 mg/m(2) on day 1, vindesine 3 mg/m(2) on days 1 and 8, and cisplatin 80 mg/m(2) on day 1. Radiotherapy directed at the tumor and the ipsilateral supraclavicular nodes was started on day 2 of each course, at the total dose of 45 Gy in 25 fractions, with a 1-week split. Thoracotomy was undertaken 2 to 4 weeks after completion of the chemoradiotherapy. Those with unresectable disease received boost radiotherapy. RESULTS From May 1999 to November 2002, 76 patients were enrolled, of whom 20 had T4 disease; 75 patients were fully assessable. Chemoradiotherapy was generally well tolerated. Fifty-seven patients (76%) underwent surgical resection, and pathologic complete resection was achieved in 51 patients (68%). There were 12 patients with pathologic complete response. Major postoperative morbidity, including chylothorax, empyema, pneumonitis, adult respiratory distress syndrome, and bleeding, was observed in eight patients. There were three treatment-related deaths, including two deaths owing to postsurgical complications and one death owing to sepsis during chemoradiotherapy. The disease-free and overall survival rates at 3 years were 49% and 61%, respectively; at 5 years, they were 45% and 56%, respectively. CONCLUSION This trimodality approach is safe and effective for the treatment of patients with SSTs.

Optimal distance of malignant negative margin in excision of nonsmall cell lung cancer: a multicenter prospective study

BACKGROUND Complete excision of nonsmall cell lung cancer is necessary during a limited resection procedure, as a malignant positive margin can lead to margin relapse. Because there is scant information available regarding the optimal size of a malignant negative margin, we conducted a multicenter, prospective study to more fully elucidate this area of concern. METHODS Two hundred five pulmonary tumors (22 nonsmall cell lung cancers and 183 undiagnosed lesions) were excised, of which 118 nonsmall cell lung cancer lesions were analyzed. Malignant status was considered positive when either a cytologic or histologic technique revealed the margin to be malignant. Maximum tumor diameter (from 4 to 45 mm with an average of 15.3 mm), margin distance (from 0 to 25 mm with an average of 9.3 mm), tumor location, extent of stapling carried out, and performance of a thoracotomy were the variables. RESULTS Seventy-two of the sample tissues (61%) were malignant negative. The negative group had smaller maximum tumor diameter, greater margin distance, lesions in more easily resectable regions, and more often required stapling only. Using a multivariate analysis, maximum tumor diameter and margin distance were found to be independent factors. The number of malignant negative margins was 7/7 (100%) when the margin distance was greater than 20 mm, and the number of malignant negative margins was 21 of 21 (100%) when the resected tumors had a margin distance greater than the maximum tumor diameter. CONCLUSIONS Malignant positive margins were not found when the margin distance was greater than the maximum tumor diameter, which was considered to be the optimal margin distance for prevention against margin relapse.

Prediction of Postoperative Respiratory Failure in Patients Undergoing Lung Resection for Lung Cancer

To evaluate the correlation between predicted postoperative lung function and postoperative respiratory morbidity, 156 patients with lung cancer who underwent resection were classified into four groups based on the degree of postoperative problems: Group 1--no problems (116 patients); Group 2--retention of sputum or atelectasis requiring bronchofiberscopy two or more times (17 patients); Group 3--tracheostomy or mechanical ventilation for more than 2 days or both (14 patients); and Group 4--postoperative death (9 patients). The mean ages of Groups 2, 3, and 4 were significantly (p less than 0.05) higher than the mean age of Group 1. The predicted postoperative lung function (F) was assessed by the formula F = [1-(b-n)/(42-n)] x f, where f is the preoperative vital capacity or forced expiratory volume in one second, b is the number of subsegments of the resected lung lobe, and n is the number of subsegments obstructed by the tumor, which was assessed by the findings on the chest tomogram, on the bronchogram, at bronchofiberscopy, or a combination of these. The total number of subsegments was assumed to be 42. The predicted postoperative % FEV1 was 65.1 +/- 19.3% in Group 1,55.3 +/- 10.6% in Group 2,37.6 +/- 12.1% in Group 3, and 42.3 +/- 18.4% in Group 4. It was significantly (p less than 0.05) different between all the groups except between Groups 3 and 4. All 10 patients with a predicted postoperative % FEV1 of less than 30% were in Groups 3 and 4. We conclude that special attention to postoperative management is needed for patients whose predicted postoperative %FEV1 is lower than 30%.

Ultra-Sensitive Detection of the Pretreatment EGFR T790M Mutation in Non–Small Cell Lung Cancer Patients with an EGFR-Activating Mutation Using Droplet Digital PCR

Purpose: The resistance to the EGFR tyrosine kinase inhibitors (TKI) is a major concern in non–small cell lung cancer (NSCLC) treatment. T790M mutation in EGFR accounts for nearly 50% of the acquired resistance to EGFR-TKIs. Earlier studies suggested that T790M mutation was also detected in TKI-naïve NSCLCs in a small cohort. Here, we use an ultra-sensitive droplet digital PCR (ddPCR) technique to address the incidence and clinical significance of pretreatment T790M in a larger cohort. Experimental Design: ddPCR was established as follows: wild-type or T790M mutation-containing DNA fragments were cloned into plasmids. Candidate threshold was identified using wild-type plasmid, normal human genomic DNA, and human A549 cell line DNA, which expresses wild type. Surgically resected tumor tissues from 373 NSCLC patients with EGFR-activating mutations were then examined for the presence of T790M using ddPCR. Results: Our data revealed a linear performance for this ddPCR method (R2 = 0.998) with an analytical sensitivity of approximately 0.001%. The overall incidence of the pretreatment T790M mutation was 79.9% (298/373), and the frequency ranged from 0.009% to 26.9%. The T790M mutation was detected more frequently in patients with a larger tumor size (P = 0.019) and those with common EGFR-activating mutations (P = 0.022), as compared with the others. Conclusions: The ultra-sensitive ddPCR assay revealed that pretreatment T790M was found in the majority of NSCLC patients with EGFR-activating mutations. ddPCR should be utilized for detailed assessment of the impact of the low frequency pretreatment T790M mutation on treatment with EGFR-TKIs. Clin Cancer Res; 21(15); 3552–60. ©2015 AACR.

Expression and prognostic significance in lung cancer of human tumor‐associated antigen RCAS1

A new monoclonal antibody (MAb), 22‐1‐1, acts against a novel tumor‐associated antigen (Ag) strongly expressed in human uterine cervical adenocarcinomas. A cDNA encoding the Ag recognized by the 22‐1‐1 MAb has been isolated and called RCAS1 (receptor‐binding cancer antigen expressed on SiSo cells). RCAS1 can induce growth arrest and apoptosis in RCAS1 receptor‐positive cells including T cells and natural killer cells in vitro. These results suggest that RCAS1 is involved in tumor escape from the immune system. Immunohistochemical analysis revealed the relationship between RCAS1 expression and clinicopathological variables (age, sex, smoking, histology, differentiation grade, pathological T factor, N factor and stage) and the prognostic significance of RCAS1 in 66 lung‐cancer patients who underwent curative operations: 33 adenocarcinomas, 24 squamous‐cell carcinomas, 3 large‐cell carcinomas, 4 adenosquamous carcinomas and 2 small‐cell carcinomas. Median follow‐up period of 64 non‐small‐cell carcinomas (NSCLCs) was 67.4 months. RCAS1 was expressed in 74.2% of lung cancers. RCAS1 in NSCLC cases with advanced T factor or pathological stage or in poorly differentiated adenocarcinomas was highly expressed. Furthermore, RCAS1 expression inducing apoptosis of tumor‐infiltrating lymphocytes was a significant prognostic factor in NSCLC (p < 0.03). Int. J. Cancer 89:488–493, 2000.

Gender, Histology, and Time of Diagnosis Are Important Factors for Prognosis: Analysis of 1499 Never-Smokers with Advanced Non-small Cell Lung Cancer in Japan

Background: There has been a growing interest in lung cancer in never-smokers. Methods: Utilizing a database from the National Hospital Study Group for Lung Cancer, information for never-smokers and ever-smokers with advanced non-small cell lung cancer was obtained from 1990 to 2005, including clinicopathologic characteristics, chemotherapy response, and survival data. Time of diagnosis was classified into two periods: 1990–1999 and 2000–2005. Multivariate analysis was performed using the Cox regression and logistic regression method, including gender, age, performance status, histology, stage, and period of diagnosis. Results: There were 1499 never-smokers and 3455 ever-smokers with advanced stage IIIB and IV diseases who received cytotoxic chemotherapy. Never-smokers generally included more females, were younger, with better performance status and more adenocarcinoma diagnosed (p < 0.0001 for all). Smoking status was a significant prognostic factor (never-smoker versus ever-smoker; hazard ratio [HR] = 0.880, 95% confidence interval [CI]: 0.797–0.970; p = 0.0105). In separate multivariate analysis for never-smokers and ever-smokers, female gender and better performance status (p < 0.0001 for both) were both favorable prognostic factors. However, adenocarcinoma histology (versus squamous cell carcinoma; HR = 0.790, 95% CI: 0.630–0.990; p = 0.0403) and the period after 2000 (versus before 2000; HR = 0.846, 95% CI: 0.731–0.980; p = 0.0254) were significant only in the never-smokers, and younger age (HR = 1.007, 95% CI: 1.003–1.011; p = 0.0010) was significant only in the ever-smokers. In an exploratory analysis, different profiles were observed in predictive factors for chemotherapy response between the two groups. Conclusions: Never-smokers with non-small cell lung cancer lived longer than ever-smokers. Gender, histology, and time of diagnosis are important factors for prognosis in these patients.

Malignant minor pleural effusion detected on thoracotomy for patients with non–small cell lung cancer: is tumor resection beneficial for prognosis?

BACKGROUND This study attempts to clarify the benefit of surgery for non-small cell lung cancer (NSCLC) with malignant minor pleural effusion that is detected at thoracotomy. METHODS Records of surgical patients with NSCLC were reviewed, with a definition of minor pleural effusion as less than 300 mL. The patients were divided into three groups as follows: (1) group C consisted of patients who underwent grossly complete resection; group I, patients with incomplete tumor resection; and group E, patients who underwent exploratory thoracotomy only. RESULTS There were 196 patients who had minor pleural effusion; of these, 96 (46%) underwent an examination to define the malignancy status of pleural effusion after surgery. In 43 patients (45%), the effusion was found to be malignant. The median survival time and 5-year survival rate, respectively, were 13 months and 9% for group C (n = 11); 34 months and 10% for group I (n = 14; p = 0.3); and 17 months and 0% for group E (n = 18; p = 0.8). CONCLUSIONS Tumor resection is not beneficial for the survival of patients with NSCLC who have a minor malignant pleural effusion.